Program Director/Principal Investigator (Santra, Santimukul): PROJECT SUMMARY/ABSTRACT Herein, we propose the development of novel magnetic relaxation nanosensor (MRnS) technology which will allow for the rapid diagnosis of influenza and further investigation of crucial viral binding mechanisms and anti- viral interventions. Our proposed MRnS are fabricated by conjugating targeting epitopes (cell receptors, peptides, antibodies) to the surface of superparamagnetic iron oxide nanoparticles. These functional MRnS are then able to bind with targeted viral proteins in solution, which is detectable using a benchtop magnetic relaxometer. Previously, we have shown that this approach allowed for the detection of as little 1 nM concentrations of viral glycoproteins within minutes. This is much faster than current diagnostic approaches, such as PCR and ELISA, which are more complex, time-consuming, and costly. We plan to further develop our MRnS technology for even more rapid and specific detection of a wider range of influenza subtypes (human, avian, swine). Furthermore, we propose the use of this MRnS technology to further investigate the viral mechanisms responsible for the biding and fusion steps of influenza infection. Using our technology, we will be able to detect binding between cell receptors and glycoproteins, as well as better visualize the effect of entry blocker peptides in this process. We have previously investigated the binding affinity between a number of entry blocker peptides and various hemagglutinin variants (H1 and H5), and plan to further investigate this with hand-in-hand computational screening of peptide databanks for the discovery of effective entry blockers. In addition, we plan to use our technology to investigate the fusion process mediated by HA2, the hemagglutinin subunit which undergoes a pH-controlled conformational change resulting fusion. We then propose to analyze the effectiveness of fusion-inhibitors for the discovery of novel anti-viral intervention methods. During the RO3 timeline, we plan to demonstrate the feasibility of using our novel MRnS technology as a rapid diagnostic tool as well as an effective investigative tool. We expect that our research will result in the development of multiple influenza subtype-specific nanosensors and the discovery of peptides that hold the potential to be used as anti-viral interventions. We also believe that this research will open the doors for magnetic relaxation technology to be used for the investigation of other pathogen systems. Page Project Summary